I think Draco Meteor's slight inaccuracy can be ignored considering bwe play Ubers UU. Zacian's Play Rough, Deoxys' Psycho Boost, and Chi-Yu's Fire Blast are all moves from A tier Pokemon constantly used for revenge killing. Tera and Substitute are definitely factors, but I'd say they're just factors that the majority of speed control has to face, I'd say Latios's ability to threaten so many things is still very worth it. While Latios can't constantly switch into Psychic, the offensive teams shouldn't be giving Landorus like 5 opportunities to come in, only exceptions are HO teams that want to use Calm Mind Latios anyway. I think losing momentum bar pivots is another flaw in speed control rather than just Latios, Landorus can thud into a Moltres or Mandibuzz, Urshifu-R into Giratina, and Chi-Yu/Landorus have to often hard switch after picking off a Pokemon, giving free turns. I think Trick can be okay by the time Latios covers for their speed control, especially since the Arceus formes shouldn't sweep when given a free turn. Tera Steel CM Latios can't break those but its a CM Pokemon that can 1v1 CM Arceus and Recovery helps it outlast Pokemon like Magearna, Solgaleo, and the Landorus it always checks. I can get the Zacian match up is far less than great, If you're Tera Dragon, the chip can be from hitting Molt with Wild Charge or taking 2 layers of spikes if its Lum. I do think Tricking Zacian is also viable, as thats similar to removing the threat. I definitely don't think it belongs with the rest of the B-tier Pokemon at least, as many of them have far less defined niches and less useful instances.
I acknowledge that a lot of our top metagame staples have moves that aren't 100% accurate and that it's not fair to hate on one Pokemon for its accuracy issues while ignoring others. That said, that is not my intention here. Zacian, Deoxys, and Chi-Yu are all still ranked in A tier
despite their accuracy issues, because the outcome, should their moves hit, is so incredibly strong. Their weakness when it comes to accuracy is offset by the sheer prowess they wield. Latios however, must contend with its accuracy issues
in addition to its lesser ability to make progress in-game. Substitute point is fair though that move equally fucks over everything. Tera however, is not something that every form of speed control has equal troubles with. Latios in particular has to contend with the fact that Tera Faerie and Tera Steel are incredibly popular Teras on offensive Pokemon, which poses a major problem since Latios almost wants to be treating Psychic like its a coverage move. Psychic-type moves are horrible to lock into in this tier, and Latios' Psychic isn't even that strong. As for the comment about how offense teams shouldn't be giving opportunities for Landorus to come in, I think that this statement is fallible in a number of ways. Good doubles, Lando coming in on a Mag Spike or Volt-Switch, Lando coming in on Arceus-Poison, Volt/Turn pivoting. While yes an offense team should indeed be limiting the number of times any opposing breaker can come in, one of the reasons Landorus is so great is because of the myriad of ways it
can come in. 5 times might be a little much, but it is not completely unheard of over the course of a game, if the Landorus-user plays well. When it comes to the point about pivot moves, I think you actually prove my point funnily enough. Both Latios and Scarfshifu struggle due to their lack of power, and rely on pivot moves to deal with their checks. And so it should be of no surprise that they're ranked in the same tier. I'd also argue that Scarf Lando is a B- tier pokemon, right below Latios. As for Chi-yu, I don't think it's at all a fair comparison. For one, Chi-yu doesn't have pivoting moves, nor does it need them. Part of why Chi-yu is so great is because it tears apart standard Mag/Gira cores. Latios on the other hand, is practically
forced to click Flip-turn if it doesn't want to be sinking momentum into most steel-types. As for Chi-yu having to often swap out after a KO, yea that's pretty fair. Although I will note though, that Chi-yu's ability to claim KOs is far more potent than Latios', and can deplete an opponent's resources very fast, making up for its occaisonal momentum sinks. As for when Latios tricks away its scarf... I'm not quite sure what you mean by "covers for their speed control", but I still think that it is never the play to click trick, unless its an endgame situation where Trick is truly required to close out the game. Choosing to give up speed control is a very dangerous gambit, that can severely limit your options over the course of a game in dealing with offensive threats. Also I highly disagree with brushing aside the importance of giving Arceus a free turn. Especially in the late game, a free turn can be all that Arceus needs to win. As for getting chip on Zacian, I acknowledge that hazards can do the trick, but sacrificing Moltres in order to chip Zacian into range is a pretty big tradeoff. Tbh, I think this moreso speaks on how problematic Zacian feels right now, but it is still relevant as it pertains to how well Latios is able to perform. All in all, I think that Latios is perfectly suited to B tier, given that it has some solid and unique roles it can fulfill, but
needs a decent amount of support in order to reliably perform well.